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Title: Non-inductive current drive and profile control in JT-60U

Abstract

Recent studies in JT-60U to establish physics base of a steady-state tokamak reactor are presented. High fusion performance with fusion triple product {ital n}{sub {ital D}}(0){tau}{sub {ital ET}}{sub {ital i}}(0)=1.2{times}10{sup 21} keVsm{sup {minus}3} (equivalent {ital Q}{sub {ital DT}}=0.6) has been achieved transiently in the high {beta}{sub {ital p}} {ital H}-mode regime. By optimizing the current and pressure profiles, a quasi steady-state high {beta}{sub {ital p}} {ital H}-mode with {ital n}{sub {ital D}}(0){tau}{sub {ital ET}}{sub {ital i}}(0)=(0.4{minus}0.5){times}10{sup 21} keVsm{sup {minus}3} (equivalent {ital Q}{sub {ital DT}}=0.25{minus}0.36) was maintained for up to 1.5 s. In order to maintain such high fusion performance discharges for a long time, non-inductive current drives and their capability of profile control were widely examined in the JT-60U tokamak. High-power ({approximately}7 MW) lower hybrid current drive (LHCD) experiments were performed by using a simplified multijunction launcher. A driven current of 3.6 MA has been achieved with a current drive efficiency of (0.3{minus}0.35){times}10{sup 20} m{sup {minus}2}A/W. Neutral beam current drive (NBCD) was also studied by using co/counter and on/off axis tangential beams ({approximately}4 MW). The maximum driven current and the current drive efficiency were 0.55 MA and 0.06{times}10{sup 20} m{sup {minus}2}A/W, respectively. Capability to control the current profile by LHCDmore » and NBCD with a wide range of the plasma current was verified. Fully non-inductively driven discharges ({ital Ip}{le}1 MA) with good energy confinement ({tau}{sub {ital E}}/{tau}{sub {ital E}}{sup ITER89P}{le}2.5) and a high fraction of the bootstrap current ({ital I}{sub {ital BS}}/{ital I}{sub {ital p}}=0.6{minus}0.7) have been obtained with NBCD and/or LHCD. These results emphasized an importance of the profile control to obtain highly integrated tokamak performance. (Abstract Truncated)« less

Authors:
 [1]
  1. Japan Atomic Energy Research Institute, Naka Fusion Research Establishment, Mukoyama 801-1, Naka-machi, Naka-gun, Ibaraki-ken (Japan)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
279545
Report Number(s):
CONF-9410130-
Journal ID: APCPCS; ISSN 0094-243X; TRN: 96:023398
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 345; Journal Issue: 1; Conference: 1994 International Conference on Plasma Physics, Foz do Iguacu (Brazil), 24 Oct - 4 Nov 1994; Other Information: PBD: Sep 1995
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; TOKAMAK DEVICES; STEADY-STATE CONDITIONS; FUSION YIELD; CURRENT-DRIVE HEATING; LOWER HYBRID HEATING; PLASMA DIAGNOSTICS; TIMING PROPERTIES; X RADIATION; EXPERIMENT PLANNING

Citation Formats

Ushigusa, K, and and the JT-60 TEAM. Non-inductive current drive and profile control in JT-60U. United States: N. p., 1995. Web. doi:10.1063/1.49014.
Ushigusa, K, & and the JT-60 TEAM. Non-inductive current drive and profile control in JT-60U. United States. doi:10.1063/1.49014.
Ushigusa, K, and and the JT-60 TEAM. Fri . "Non-inductive current drive and profile control in JT-60U". United States. doi:10.1063/1.49014.
@article{osti_279545,
title = {Non-inductive current drive and profile control in JT-60U},
author = {Ushigusa, K and and the JT-60 TEAM},
abstractNote = {Recent studies in JT-60U to establish physics base of a steady-state tokamak reactor are presented. High fusion performance with fusion triple product {ital n}{sub {ital D}}(0){tau}{sub {ital ET}}{sub {ital i}}(0)=1.2{times}10{sup 21} keVsm{sup {minus}3} (equivalent {ital Q}{sub {ital DT}}=0.6) has been achieved transiently in the high {beta}{sub {ital p}} {ital H}-mode regime. By optimizing the current and pressure profiles, a quasi steady-state high {beta}{sub {ital p}} {ital H}-mode with {ital n}{sub {ital D}}(0){tau}{sub {ital ET}}{sub {ital i}}(0)=(0.4{minus}0.5){times}10{sup 21} keVsm{sup {minus}3} (equivalent {ital Q}{sub {ital DT}}=0.25{minus}0.36) was maintained for up to 1.5 s. In order to maintain such high fusion performance discharges for a long time, non-inductive current drives and their capability of profile control were widely examined in the JT-60U tokamak. High-power ({approximately}7 MW) lower hybrid current drive (LHCD) experiments were performed by using a simplified multijunction launcher. A driven current of 3.6 MA has been achieved with a current drive efficiency of (0.3{minus}0.35){times}10{sup 20} m{sup {minus}2}A/W. Neutral beam current drive (NBCD) was also studied by using co/counter and on/off axis tangential beams ({approximately}4 MW). The maximum driven current and the current drive efficiency were 0.55 MA and 0.06{times}10{sup 20} m{sup {minus}2}A/W, respectively. Capability to control the current profile by LHCD and NBCD with a wide range of the plasma current was verified. Fully non-inductively driven discharges ({ital Ip}{le}1 MA) with good energy confinement ({tau}{sub {ital E}}/{tau}{sub {ital E}}{sup ITER89P}{le}2.5) and a high fraction of the bootstrap current ({ital I}{sub {ital BS}}/{ital I}{sub {ital p}}=0.6{minus}0.7) have been obtained with NBCD and/or LHCD. These results emphasized an importance of the profile control to obtain highly integrated tokamak performance. (Abstract Truncated)},
doi = {10.1063/1.49014},
journal = {AIP Conference Proceedings},
number = 1,
volume = 345,
place = {United States},
year = {1995},
month = {9}
}